Open Hopper, 5-Bay Ortner Rapid Discharge

History: The 1960s brought about a growth in car size (and capacity). Railroads that transported coal moved away from the older 2-bay 55-ton USRA standard to newer railcars. The Ortner Rapid discharge car has a capacity of 100 tons. Over 10,000 cars of this kind were produced. Robert Ortner and a team of engineers created the rapid-discharge door system in the early 1960s. The original unit train consists were operating for Muskingum Electric Railroad (now AEP) and the Missouri Public Service Co.

Unloading a train of rapid discharge cars takes 30 minutes to an hour as opposed to four hours or longer for other unloading systems. Southern developed the unit train concept in 1960. Unit trains shuttle back and forth between mines and power plants. The first unit trains, composed of aluminum gondolas, went to power plants with rotary dumping facilities. Today, Southern has 14 unit coal trains on line; six in immediate prospect; and several others in longer range planning. While passing over a 900-foot long trestle, rapid discharge cars unload their coal in motion. Doors in the bottom of the cars are activated electrically.

Trinity Industries Inc. purchased Ortner Freight Car in late 1986 and continues to develop the rapid-discharge system with both updated transverse and longitudinal door applications. Trinity currently offers aluminum hoppers featuring the RDVI and RDL door systems.